Missing validation when generating new entry

[MootezSaaD]

• I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

When the ID field is left blank and the user clicks on the Generate button, an NPE would be thrown
Steps to reproduce the behavior:

1. Library
2. New Entry
3. Leave ID field blank
4. Click on Generate

Maybe disabling the Generate button until an adequate value is entered could fix the issue.

Log File

java.lang.NullPointerException
at java.base/java.util.regex.Matcher.quoteReplacement(Unknown Source)
at org.jabref/org.jabref.logic.l10n.LocalizationKeyParams.replacePlaceholders(Unknown Source)
at org.jabref/org.jabref.logic.l10n.Localization.lookup(Unknown Source)
at org.jabref/org.jabref.logic.l10n.Localization.lang(Unknown Source)
at org.jabref/org.jabref.gui.EntryTypeViewModel.lambda$runFetcherWorker$1(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.concurrent.EventHelper.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.concurrent.Task.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.concurrent.Task.setState(Unknown Source)
at org.jabref.merged.module/javafx.concurrent.Task$TaskCallable.lambda$call$2(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.win.WinApplication._enterNestedEventLoopImpl(Native Method)
at org.jabref.merged.module/com.sun.glass.ui.win.WinApplication._enterNestedEventLoop(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.Application.enterNestedEventLoop(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.EventLoop.enter(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.QuantumToolkit.enterNestedEventLoop(Unknown Source)
at org.jabref.merged.module/javafx.stage.Stage.showAndWait(Unknown Source)
at org.jabref.merged.module/javafx.scene.control.HeavyweightDialog.showAndWait(Unknown Source)
at org.jabref.merged.module/javafx.scene.control.Dialog.showAndWait(Unknown Source)
at org.jabref/org.jabref.gui.importer.NewEntryAction.execute(Unknown Source)
at org.jabref/org.jabref.gui.actions.JabRefAction.lambda$new$2(Unknown Source)
at org.jabref.merged.module/org.controlsfx.control.action.Action.handle(Unknown Source)
at org.jabref.merged.module/org.controlsfx.control.action.Action.handle(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.scene.control.MenuItem.fire(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.scene.control.ContextMenuContent$MenuItemContainer.doSelect(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.scene.control.ContextMenuContent$MenuItemContainer.lambda$createChildren$12(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.event.Event.fireEvent(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$MouseHandler.process(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene.processMouseEvent(Unknown Source)
at org.jabref.merged.module/javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at org.jabref.merged.module/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.View.notifyMouse(Unknown Source)
at org.jabref.merged.module/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at org.jabref.merged.module/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)